Apparatus for preshaping uppers



March 21, 1967 D. R. DEW 3,39,?23

APPARATUS FOR PRESHAPING UPPERS Original Filed April 24, 1964 4 Sheets-Sheet l lNVE/VTO/E Dav/d fiobari Dew March 21, 1967 D. R. DEW

APPARATUS FOR PRESHAPING UPPERS Original Filed April 24, 1964 4 Sheets$heet 2 fiTTO/PA/EYS D. R. DEW

March 21, 1967 APPARATUS FOR PRESHAPING UPPERS 4 Sheets-Sheet 5 Original Filed April 24, 1964 fA/VENTQR ATTORNEYS smwza D. R. DEW

March 21, 1967 APPARATUS FOR PRESHAPING UPPERS 4 Sheets-Sheet Original Filed April 24, 1964 United States Patent Office 3,309,723 Patented Mar. 21, 1967 3,3il9,723 APPARATUS FOR PRLSHAPMG UPPERS David Robert Dew, Kettering, England, assignor to The British Boot, Shoe and Allied Trades Research Association, Kettering, England, a British association Original application Apr. 24, 1964, Ser. No. 352,365. Divided and this application Oct. 5, 1965, Ser. No. 493,190 Claims priority, application Great Britain, Apr. 25, 1963, 16,382/63 Claims. (Cl. 12-541) This invention relates to the shaping of leather, and in particular to the shaping of upper parts in the course of manufacturing footwear. This application is a division of my co-pending application Ser. No. 362,365 filed Apr. 24, 1964.

The traditional method of making leather footwear depends upon straining the upper material, which is usually more or less flat in its initial form, over the making last, after which the leather is left on the last for an extended period of time so that the leather will retain to a large extent the shape into which it has been pulled, after the last has been removed. More recently, various processes have been evolved directed to the reduction of the time the footwear must remain on the last to obtain a satisfactory degree of shape retention. In particular attention has been directed to the phenomenon known as heat setting, that is to say, the retention by the leather of the stretch which has been imparted to it, if the stretched leather is force dried whilst it is damp. In this connection, it has more recently been discovered that the shape retention is much more pronounced, if the leather is moistened or is additionally moistened in its stretched condition.

It is an object of the present invention to provide new and useful methods of applying these recent discoveries to the preshaping of the shoe uppers, by which is meant the shaping of the uppers prior to their application to the last with a view to making them fit the last more readily, It is another object of the invention to provide means of devising improved and more economical patterns for cutting leather uppers. Yet another object is to provide means for reducing the tension and stressing which is normally required in lasting shoe uppers.

The invention consists, broadly, in a method of preparing shoe upper foreparts (Vamps) for lasting, which comprises marginally clamping the forepart at prede termined positions, selectively stretching the forepart along regions adjacent and generally parallel to its lateral margins, and setting the stretch in the forepart material. Preferably, in addition, the forepart is selectively stretched in the tab point regions in a direction generally at right angles to the previously mentioned stretch.

The setting of the stretch in the leather signifies that a substantial proportion of the stretch remains after the tension is removed from the upper material. This may as already mentioned be accomplished by heat setting, or even merely by the application of moisture to the stretched upper. When heat setting is employed, the leather may be moistened before or after it is stretched, or both. It is a feature of the invention that the moisture and/or heat may also be applied selectively, as a means of localising the set in the leather. Thus, a smaller degree of residual stretch is required in the lasting margin than in the lateral marginal portions of the upper immediately above the lasting margins. Where the lateral marginal portions of the forepart, including the lasting margins, are stretched, moisture and/or heat may be applied selectively to the lateral regions of the forepart above the lasting margin so that the latter may subsequently be turned under with little or no wrinkling.

The location and extent of strains which need to be applied to a shoe upper to cause it to conform to the surface of a last can be determined according to a further feature of the invention, by flattening shells of the last made from suitable material such as tape or plastics material. In order to achieve the flattening of the shell, the material must of course be shrunk in various regions, and this can be accomplished for example by pleating it. The extent of the required shrinkage can then be measured, and in this way a pattern can be prepared showing the starting contour and the location and degree of stretch required so to pre-shape the initially flat upper material that it will conform to the last with a minimum of strain. To achieve this, however, it is necessary to strain the upper in a manner which cannot be achieved by existing lasting machinery, These operations will normally be carried out on the Vamps of boots and shoes, with or without tongues, which extend back beyond the joint line of the last.

The invention also provides a novel construction of machine for straining upper parts as aforesaid. This machine comprises spaced clamps for gripping the leather at spaced positions, means for moving the closed clamps to increase the separation therebetween, and means for applying heat and/or moisture to the leather stretched between the clamps. Preferably, the machine comprises also means for stretching the leather at an angle to the direction of increase in separation between the closed clamps. In a preferred arrangement, two clamps are provided, each comprising a pair of jaws arranged to close up to a central jaw member for engaging opposite marginal portions of a folded vamp, whilst the means for stretching the leather across the direction from one clamp to the other comprises a bar and means for pushing the bar into the fold of the vamp. The machine may comprise heated members on mounts arranged for moving the heated members up to the folded vamp between the clamps. For the introduction of moisture, retractable water permeable webs may be employed, arranged for movement into a position between the heated side plate and the folded vamp.

The invention will be described further with reference to the accompanying drawings, of which:

FIGURE 1 is a plan view of a leather vamp cut to a pattern in accordance with this invention and prior to stretching,

FIGURE 2 is a view similar to FIGURE 1 but of a different pattern,

FIGURE 3 is a view of the essential parts of a machine for stretching Vamps in accordance with the invention,

FIGURE 4 is a view similar to FIGURE 3 but showing the machine loaded and in operation; Whilst FIGURE 5 is a diagrammatic elevation of a somewhat modified machine.

The vamp shown in FIGURE 1 comprises a tongue 1, tab points 2, a toe portion 3 and marginal side portions generally indicated by the reference numeral 4. The feather line, that is to say the line along which the lasting margin is folded under the last, is indicated by the dotted line 5. A forepart pattern such as that shown in FIGURE 1 can in considerable measure be generated by forming a skin or shell of flexible material on the last over the required area, removing the skin or shell and flattening it. In order to accomplish this flattening, it will be found that extensive pleating or wrinkling of the flexible material is necessary. This corresponds in effect to a compression of the material, and the direction and extent of the more important lines of compression are indicated by reference numerals 6 and 7 in FIGURE 1. Correspondingly, to generate the original shell, a

leather pattern cut to the shape shown in FIGURE 1 requires to be stretched in the corresponding direction and to the corresponding extent. Similarly in FIGURE 2, where the same numerals identify corresponding parts of the vamp, which in this case has no tongue, the marginal portions 4 are stretched over the region indicated from an initial length of 4 inches to a final length of 4- /2 inches, whilst the region of the tab points is given a stretch of the order of of an inch. These two directions of stretch are not, of course, by any means precisely at right angles to one another but they are generally transverse to one another.

In stretching a vamp such as shown in FIGURE 1 or FIGURE 2, it may be found advantageous not to stretch the lasting margin itself to the extent indicated, or at least to arrange that the stretch is not retained to the same extent as it is above the lasting margin. This can be accomplished in the manner already explained.

The machine illustrated in FIGURES 3 and 4 cornprises a central jaw block 8 and jaw members 9 arranged to close up to the block 8 for the purpose of engaging the toe portion of a folded vamp 10 as shown in FIGURE 4. These jaws 9 are mounted on levers 11 arranged through a further lever system 12 to swing the jaws into a gripping position under the influence of a pneumatic ram 13. The whole assembly of levers, jaws and ram is mounted on a sliding plate 14 arranged for movement by a further pneumatic ram (not shown). A like jaw block 15, spaced from the jaw block 8 in the direction of movement of the plate 14, is associated in turn with a pair of jaws 16. These jaws are arranged to close up to the jaw block 15 under the influence of a further pneumatic ram (not shown). They grip the rear part of the folded vamp 10 as illustrated in FIG- URE 4. Mounted above and extending generally between the blocks 8 and 15 is a curved bar 17 which is hingedly mounted above yet another pneumatic ram (not shown) for lifting the bar 17 vertically. As shown in FIGURE 4, the bar 17 is so shaped that it will conform with the fold of the vamp 10. Side plates 18, associated with respective heating elements 19, are arranged for movement under the influence of pneumatic rams 20 to close about the folded vamp 10.

FIGURES 3 and 4 show the essential parts of the machine. It will be appreciated that arrangement of pneumatic circuitry to accomplish the desired machine movements in a proper timed sequence is a matter presenting no difficulty to those skilled in the art, and for the sake of clarity these details have therefore been omitted. In operation, the previously moistened vamp 10 is draped over the lowered bar 17 and the toe part is positioned over the block 8. Ram 13 is then actuated, for example by a pedal (not shown) causing the jaw members 9 to grip the vamp firmly. The two sides of the vamp are then positioned over the fixed block 15 which, with the jaw members 16 forms another double clamp. The vamp is tensioned lightly by hand, and located so that it is positioned squarely between the two double clamps. The clamp 15, 16 is then closed by actuation of the corresponding ram. Desirably, subsequent operations follow an automatic sequence.

The first movement of the sequence is for the plate [14 to be retracted under the influence of its respective pneumatic ram until a predetermined stop is reached, thus stretching the vamp. The stop, or the initial position of the plate 14, may be made adjustable to regulate the degree of stretch. Next, the bar 17, which is pivotally mounted on the pushrod of the respective pneumatic ram, is caused to rise so that any wrinkles which have been formed in the vamp 10 by stretching it are removed, whilst the vamp is further stretched particularly in the region of the tab points and in a direction generally transverse to that occasioned by the separation of the block 8 from the block 15. Then, the two 'heated side plates 18 move inwardly, and are pressed firmly into contact with the vamp. Drying can, if desired, be assisted by directing a stream of hot air into the space between the side walls of the vamp. The effect of this treatment, the duration of which is desirably controlled by a timer and will normally be of the order of 10 seconds, is to impart a considerable degree of set to the leather. The movements of the machine are now reversed in the same sequence.

The area of the vamp which is heat set is determined by the dimensions of the heated side plates 18, which may be modified as desired.

In a simple modification, which is not illustrated, a further pair of plates is provided arranged for vertical reciprocation between the side plates 18 and the bar 17. These plates are of water permeable material and are arranged to be charged with water when they are lifted to a position between the side plates 18 and the bar 17. In this way, when the side plates 18 move in to press against the vamp 10, they press the additional, watercharged plates against the side of the vamp. This accomplishes the desired moist heat setting of the stretched leather, without the necessity of moistening the vamp beforehand. Again, the inclusion of the pneumatic rams and the corresponding provision in the pneumatic circuitry for these rams to operate in the proper sequence is an elementary matter not requiring further explanation.

For the purpose of charging the water permeable plates with water, a water reservoir may be provided below the bar 17 so that the plates are lifted out of this water each time they are to be used. The plates may in this case comprise a gauze for example a metal gauze. If this water reservoir is not desired, the plates may for example be sprayed as they rise into position.

The modified machine shown in FIGURE 5 comprises a main frame 60. This carries a carriage 61 which is able to slide axially in slides attached to part 60. On this carriage is the toe clamp 62 and its pressure pad 63 which is actuated by pneumatic cylinder 64. Attached beneath the main frame are another set of slides guiding the carriage 65, to which is fixed a pneumatic cylinder 66. This is connected to 61 by a downward extension from the latter. The position of 65 in its slides and hence of 61 is controlled by the screw 67 rotated by adjusting wheel 68. The stroke of the carriage 61 in its slides is determined by the stop 69 controlled by screw 70, rotated by adjusting wheel 71.

Fixed to the front of the main frame 60 is the front clamp 72 and its pressure pads 73 actuated by pneumatic cylinder 74 which is rigidly fixed to 60. Above the two clamps is an interchangeable curved bar 75 of semi-circular cross-section, pivotally mounted to the piston rod 76 of pneumatic cylinder 77. This cylinder may be adjusted angularly and co-axially to the clamp axis by simple mechanical means not shown.

On both sides of the bar 75 are a pair of flat plates 78 shaped to suit a range of vamp sizes. These plates are attached to heated, thermostatically controlled blocks 79 and are readily interchangeable. They are pressed against the vamp through the action of pneumatic cylinder rods 80..

In operation the previously wetted vamp is folded lengthwise by hand with the wetted side outermost. (Normally this will be the flesh side of the leather.) The position and the length of stretch of the carriage 61 being pre-adjusted to the required positions, the vamp is loaded into the toe and front Clamps and stretched in the manner already described. The bar 75 is then thrust into the fold of the vamp removing wrinkles and stretching in the area of the tab points i.e. mainly between the highest position of the leather on the bar 75 and the front clamp 72. The plates 78 then advance and are pressed against the moistened leather for a predetermined time, thus heat setting the leather as before.

The machine may be used with leather uppers, with or without leather or fabric linings, the temperature of the hot side plates being adjusted according to the ""tannage of the leather. Leathers with impermeable coatings can be used, although the results will not in general be as satisfactory as those which may be obtained when rapid evaporation of moisture can take place from the face of the leather. Very satisfactory results can be obtained with materials having thermoplastic coatings, and a cold air blast directed into the space within the folded over vamp may be used to chill the surface after heating and before the applied strains are released.

If the back of the material would be marred by contact with heated blocks, alternative methods of heating include a hot air blast directed onto one or both sides of the materials, and the use of dielectric heating. For leathers, the temperature of the heated blocks will normally be within the range of 70 0-400 C.

I claim:

1. Apparatus for preshaping upper foreparts comprising two clamps, each comprising a pair of jaws arranged to close up to a central jaw member for engagim opposite marginal portions of a folded forepart; means for increasing the separation between the two closed clamps; a bar associated with means for pushing the bar into the fold of the forepart; heating means on mounts arranged for moving the heating means up to the folded vamp Where it is stretched between the clamps; and retractable waterpermeable webs arranged for movement into position between the heating means and the folded vamp.

2. Apparatus for preshaping for lasting an upper forepart comprising means, including spaced clamping means located in positions to engage the lateral marginal portions of the forepart at the toe portion and at the points of the waist, for stretching the material of the forepart lying between the clamped toe portion and the clamped points in direction ssubstantially parallel to said lateral marginal portions.

3. Apparatus, as defined in claim 2, which includes means for applying heat and/ or moisture to the material stretched between the clamps.

4. Apparatus, as defined in claim 2, in which the means for stretching the forepart comprises means for relatively separating the clamping means at the toe portion and the clamping means at the waist points in a line substantially parallel to said lateral marginal portions.

5. Apparatus, as defined in claim 2, in which there are means for stretching the waist portion between said lateral marginal portions in directions transverse to the directions of the lateral marginal portions.

6. Apparatus, as defined in claim 5, which includes means for applying heat and/ or moisture to the material stretched between the clamps.

7. The apparatus, as defined in claim 5, in which the means for stretching the waist portion of the forepart comprises a member positioned to engage the marginal portion of the forepart extending between the point clamps.

8. Apparatus for prestretching for lasting an upper forepart comprising a bar over which the forepart is draped to depend therefrom substantially equally at both sides of the bar; first clamping means engaging the marginal portion of the points of the forepart at each side of the bar; second clamping means engaging the marginal portions of the toe portion of the forepart at each side of the bar; means for closing both clamping means to grip the material of the forepart; and means for causing rela' tive separating movement of the first and second clamping means to stretch the lateral marginal portions of the forepart in directions substantially parallel to said marginal portions.

9. Apparatus, as defined in claim 8, in which there are means for causing relative movement between the first clamping means and the bar to stretch the marginal portions of the forepart lying between the first clamping means in directions substantially transverse to the lateral margins of the forepart.

10. Apparatus, as defined in claim 9, which includes means for applying heat and/ or moisture to the material stretched between the clamps.

References Sited by the Examiner UNITED STATES PATENTS 150,630 5/1874 Talpey 12-54.1 967,586 8/1910 Thorel 12-54.1 1,110,323 9/1914 Hamilton 1254.2 X 1,195,967 8/1916 Brock 1254,2

FOREIGN PATENTS 59,014 5/1913 Austria.

PATRICK D. LAWSON, Primary Examiner. 

1. APPARATUS FOR PRESHAPING UPPER FOREPARTS COMPRISING TWO CLAMPS, EACH COMPRISING A PAIR OF JAWS ARRANGED TO CLOSE UP TO A CENTRAL JAW MEMBER FOR ENGAGING OPPOSITE MARGINAL PORTIONS OF A FOLDED FOREPART; MEANS FOR INCREASING THE SEPARATION BETWEEN THE TWO CLOSED CLAMPS; A BAR ASSOCIATED WITH MEANS FOR PUSHING THE BAR INTO THE FOLD OF THE FOREPART; HEATING MEANS ON MOUNTS ARRANGED FOR MOVING THE HEATING MEANS UP TO THE FOLDED VAMP WHERE IT IS STRETCHED BETWEEN THE CLAMPS; AND RETRACTABLE WATERPERMEABLE WEBS ARRANGED FOR MOVEMENT INTO POSITION BETWEEN THE HEATING MEANS AND THE FOLDED VAMP. 